Until the 1920's breast cancer history consisted of little more than a compilation of many case histories. Each victim of breast cancer could provide the historian with a different view of the trials faced by someone who has been found to have a breast tumor. Then during the 1920's an inventor introduced an important, new imaging technique.
That invention used small amounts of radiation to take pictures of the human breast. It allowed detection of a breast tumor before it had become large enough to show-up during a breast examination. That invention was called a mammogram, and statistics from breast cancer history have shown that it can detect 85% of the breast cancer tissue.
Breast cancer history also demonstrates the need for improvements in the mammogram. At present, the pictures from a mammogram show the fat in the breast as black and the fibrous glandular tissue of the breast as white. Cancerous tissue is also white. Therefore, a breast cancer shows up most clearly when it lies within fatty breast tissue.
In the middle of the 20th Century the emphasis on detection of breast tumors provided the primary topic for any writer of ongoing breast cancer history. Young girls were taught how to perform self-examination of their breasts. They also learned about the importance of the mammogram, especially for women over 40.
By the close of the 20th Century, advances in molecular biology had begun to require a lengthy and detailed addition to the record of breast cancer history. In 1994 researchers announced discovery of a genetic mutation that could cause breast cancer. They called it BRCA1. In 1995 other researchers found a second mutated gene, a gene that could cause breast cancer. They called that gene BRCA2.
Those discoveries helped to explain the reason that some physicians had observed a family history of breast cancer among certain patients. Those patients tended to have an early onset of breast cancer, a cancer in both breasts, cancer of the ovary (in addition to breast cancer) or knowledge of a male family member who had had breast cancer. Eventually patients with a family history of cancer were advised to get annual mammograms starting at the age of 30.
The history of breast cancer provided physicians with a greater insight into the factors responsible for breast cancer. Healthcare providers used that information to design specific questions for mammogram patients. Those patients were asked when they had had their first child and when they had begun menopause. They were also asked to provide the healthcare providers with their exact age. All of that information helped to fill the growing data sheet that throws light on the basis of breast cancer.
Researchers provided even more data. In February of 2002 a researcher in Australia announced the discovery of BRCA3. Molecular biology had uncovered yet a third mutation that could cause breast cancer. Breast cancer history had reinforced the importance of the research conducted by skilled molecular biologists.